1. Field of the Invention
The present invention relates to a capacitor sensor capable of controlling sensitivity, wherein the capacitor sensor can measure the magnitude and direction of a shear force applied to the sensor, as well as the magnitude of a normal force applied on the surface of the sensor, and consists of a single cell including a pattern electrode capable of varying its shape to control the sensitivity of the sensor.
2. Discussion of Related Art
A capacitor sensor measures a change in capacitance caused by an external force to sense the external force. The capacitor sensor includes a dielectric material and electrodes disposed at both sides of the dielectric material.
A conventional capacitive sensor measured a change in capacitance due to a change in area and depth caused by a force applied to a sensing surface, and estimated the magnitude and direction of the force based on the change in capacitance. An example of such a conventional capacitive sensor is shown in FIG. 1. As shown in FIG. 1, the conventional capacitive sensor measures a change in capacitance of each of four cells to estimate the magnitude and direction of a force applied from the outside. Technology related to the conventional capacitive sensor is disclosed in “Normal and Shear Force Measurement Using a Flexible Polymer Tactile Sensor with Embedded Multiple Capacitors”, Journal of Microelectromechanical Systems, vol. 17, No. 4, August 2008.
As such, in the conventional technology, in order to measure the magnitude and direction of an external force, four cells needed to be used, which makes the structure of a capacitor sensor complicated. Accordingly, there is increasing demand for a sensor having a simple structure and capable of controlling sensitivity.